煤烟凝聚粒子对紫外光散射信道的影响研究

Effect of Soot Aggregates on Light Scattering in Ultraviolet Communication Channels

针对具有不同粒子数量的煤烟气溶胶,使用团簇-团簇凝聚(CCA)模型形成4球、16球凝聚模型,并结合单个气溶胶粒子的吸湿性以及凝聚粒子的分形理论,生成了包覆水层的凝聚粒子模型。利用离散偶极子近似(DDA)方法仿真分析包覆水层的煤烟气溶胶的散射特性,仿真结果表明,相对湿度的增大对回转半径≤40 nm的凝聚粒子的消光因子、散射因子和吸收因子的影响最大。使用无线紫外光单次散射脉冲响应模型分析了凝聚粒子以及相对湿度对紫外光脉冲响应和路径损耗的影响,仿真结果表明,凝聚粒子和相对湿度对紫外光的通信影响集中在半径较小(r0≤40 nm)的单体粒子上。当单体粒子半径一定时,组成凝聚体的粒子数量越大或者凝聚粒子相对湿度越大,脉冲响应就越大,路径损耗越小,紫外光接收端信号越好。

In this study,a cluster-cluster aggregation(CCA)model was used to form 4-sphere and 16-sphere aerosol aggregate models for different numbers of soot aerosol particles.By combining the hygroscopic nature of individual aerosol particles and the fractal theory of aerosol aggregates,a model for aerosol aggregates covering a water layer was generated.The scattering characteristics of soot in the coating layer were simulated and analyzed using the discrete dipole approximation(DDA).Simulation results show that an increase in relative humidity has the greatest influence on the extinction,scattering,and absorption of aerosol aggregates with a rotation radius≤40 nm.Furthermore,the influence of aerosol aggregates and relative humidity on the UV pulse response and path loss was analyzed using a single-scattering pulse response model.The simulation results show that the effects of aerosol aggregates and relative humidity on UV communication are concentrated on monomer particles with smaller radii(r0≤40 nm).When the radius of the monomer particles is fixed,if the number of particles forming a cluster or the relative humidity of the aerosol aggregates increases,the pulse response is larger,the path loss is smaller,and the signal at the UV receiver is better.